This invention relates to a synergic antioxidant mixture intended to protect lipids against oxidation. The current trend in the field of antioxidants, particularly for use in foods, is to give preference to natural compounds showing antioxidant activity.
Esters of ascorbic acid with saturated fatty acids, particularly ascorbyl palmitate (AP) and ascorbyl stearate (AS), are known as antioxidants for lipids. This is also the case with tocopherols (TL) which have been found to show antioxidant activity in animal fats in which they are not naturally present. It is also known that a mixture of AP and TL is more active than each of these compounds on its own.
It has also been shown, for example by G. Pongraz in In.J.Vit.Nutr.Res. 43 (1973), that lecithin (LC), although not having any antioxidant activity of its own, greatly increases the activity of mixtures of AP and TL in butter oil and in sunflower seed oil.
This observation is confirmed in published Japanese patent application no. 80.069688 which relates to a mixture of AS, TL and LC in safflower oil and in lard.
In these known mixtures, the ascorbic acid (AA) is not used as such, but in ester form (AP, AS) for the simple reason that it is not liposoluble. According to G. Pongraz in the Article cited above, AP and AS are equivalent from the point of view of their antioxidant activity in lipids, preference being attributed to AP by virtue of its slightly better liposolubility.